The present invention relates to pulmonary delivery of active agents. Acylated or sulfonated amino acids are used as carriers to facilitate pulmonary delivery of active agents to a target.
Conventional means for delivering active agents are often severely limited by biological, chemical, and physical barriers. Typically, these barriers are imposed by the environment through which delivery occurs, the environment of the target for delivery, or the target itself. Biologically or chemically active agents are particularly vulnerable to such barriers.
For example, in the delivery to animals of biologically active or chemically active pharmacological and therapeutic agents, barriers are imposed by the body. Examples of physical barriers are the skin and various organ membranes that must be traversed before reaching a target. Chemical barriers include, but are not limited to, pH variations, lipid bi-layers, and degrading enzymes.
Pulmonary delivery to the circulatory system for many biologically active agents could be the route of choice for administration to animals because delivery to the blood is much more rapid than with other routes of delivery. In addition, delivery to the lung itself may be desired, e.g., for treatment of ailments of the pulmonary system. However, pulmonary delivery may not be practical because of physical barriers such as lipid bi-layers, and membranes that are relatively impermeable to certain biologically active agents, but which must be traversed before an agent can reach the circulatory system. In other cases, pulmonary delivery may be achieved, but not efficiently enough for practical purposes.
There is presently a need for simple, inexpensive pulmonary delivery systems which are easily prepared and which can deliver a broad range of active agents in an efficient manner.